/* Siconos is a program dedicated to modeling, simulation and control
 * of non smooth dynamical systems.
 *
 * Copyright 2024 INRIA.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#ifndef NONSMOOTHNEWTON_H
#define NONSMOOTHNEWTON_H

/*!\file NonSmoothNewton.h
  Typedef and functions declarations related to non-smooth Newton solver

  Solve \f$ \phi(z) = 0 \f$ using a Newton method.

  The algorithm is alg 4.1 of the paper of Kanzow and Kleinmichel, "A new class of semismooth
  Newton-type methods for nonlinear complementarity problems", in Computational Optimization
  and Applications, 11, 227-251 (1998).

 */

#include "NumericsFwd.h"    // for SolverOptions
#include "SiconosConfig.h"  // for BUILD_AS_CPP // IWYU pragma: keep

/* Pointer to function that corresponds to the function \f$ \phi \f$ */
typedef void (*NewtonFunctionPtr)(int, double*, double*, int);

enum NONSMOOTH_NEWTON_SOLVER { SICONOS_NONSMOOTH_NEWTON_LSA = 11000 };

extern const char* const SICONOS_NONSMOOTH_NEWTON_LSA_STR;

#if defined(__cplusplus) && !defined(BUILD_AS_CPP)
extern "C" {
#endif
/** Armijo Linesearch
 *  \param n size of the vector z
 *  \param z unknown vector
 *  \param dir search direction
 *  \param psi_k initial value of the merit function
 *  \param descentCondition descent condition
 *  \param phi pointer to function used to compute phi(z)
 */
void linesearch_Armijo(int n, double* z, double* dir, double psi_k, double descentCondition,
                       NewtonFunctionPtr* phi);

/** Newton solver with line Search
\param n size of the vector z
\param z unknown vector, in-out argument
\param phi pointer to \f$ \phi \f$ function
\param jacobianPhi pointer to \f$ \nabla_z \phi(z) \f$ function
\param iparam vector of int parameters:
 - [0] : max. number of iterations
 - [1] : number of iterations processed
\param dparam vector of double parameters:
 - [0]: tolerance
 - [1]: error
\return int 0 if ok
*/
int nonSmoothNewton(int n, double* z, NewtonFunctionPtr* phi, NewtonFunctionPtr* jacobianPhi,
                    SolverOptions* options);

/** Newton solver without line Search
\param n size of the vector z
\param z unknown vector, in-out argument
\param phi pointer to \f$ \phi \f$ function
\param jacobianPhi pointer to \f$ \nabla_z \phi(z) \f$ function
\param iparam vector of int parameters:
 - [0] : max. number of iterations
 - [1] : number of iterations processed
\param dparam vector of double parameters:
 - [0]: tolerance
 - [1]: error
\return int 0 if ok
*/
int nonSmoothDirectNewton(int n, double* z, NewtonFunctionPtr* phi,
                          NewtonFunctionPtr* jacobianPhi, SolverOptions* options);
/** @addtogroup SetSolverOptions
    @{
*/
void nonSmoothNewton_set_default(SolverOptions* options);
/** @} */

#if defined(__cplusplus) && !defined(BUILD_AS_CPP)
}
#endif

#endif
